About William
๐ Hi, I'm an AI-Powered Full-Stack Engineer helping startups and FinTech companies build intelligent digital products that solve real business problems.
I specialize in developing ๐๐ฉ๐ฉ๐ฅ๐ข๐๐๐ญ๐ข๐จ๐ง๐ฌ, ๐ฆ๐จ๐๐ข๐ฅ๐ ๐๐ฉ๐ฉ๐ฌ, automation systems, and scalable backend solutions.
Whether you're validating a ๐ฌ๐ญ๐๐ซ๐ญ๐ฎ๐ฉ ๐ข๐๐๐, launching an ๐๐๐, integrating ๐๐ into your business, building a ๐
๐ข๐ง๐๐๐๐ก ๐ฉ๐ซ๐จ๐๐ฎ๐๐ญ, or scaling an existing platform, I can help transform your vision into a production-ready solution.
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- AI SaaS Launch: Built a complete web/mobile solution (backend, AI, payments) for a startup, driving quick validation.
- FinTech Automation: Delivered secure application architecture and intelligent automation, reducing manual work.
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- AI & Automation: LLM/OpenAI integration, AI agents, chatbots, workflows, and automated document processing.
- SaaS & Startups: End-to-end MVPs, subscription billing (Stripe), dashboards, and product scaling.
- FinTech & Security: Secure financial apps, transaction workflows, RBAC, and compliant data protection.
- Web & Mobile: Responsive web apps and cross-platform mobile solutions (iOS/Android).
--------------- ๐๐ฃ๐๐ช๐จ๐ฉ๐ง๐ฎ ๐๐๐๐ฉ ๐ ๐๐๐ฃ ๐ฌ๐ค๐ง๐ ------------------
Startups, SaaS, FinTech, AI-First & Growing Tech Companies.
๐ฌ Whether you need an AI Engineer, Full-Stack Developer, SaaS Developer, or MVP Expert , let's discuss your project!
English
Native or bilingual
Can work on-site
Berlin (up to 50km)
Experience
- Mid-Tier U.S. Technology CompanySenior Full-Stack AI & Automation DeveloperJanuary 2021 - January 2025 (4 years)- Designed and delivered AI-powered automation systems that reduced manualworkload by 70%+ and improved operational efficiency 2โ5x.- Built and deployed enterprise-grade LLM systems, including RAG pipelines,document-AI tools, and multi-agent workflow assistants.- Developed full-stack platforms using React, Next.js, Node.js, and Typescript,supporting high-traffic operations with 99.9% uptime.- Engineered automation workflows using n8n, Make, webhooks, and serverlessfunctions, optimizing internal and client-facing processes.- Created custom AI chatbots and assistants that reduced support costs by 40% and accelerated response times.- Architected secure and scalable backend APIs, integrating with payment providers,CRMs, ERPs, and various third-party services.- Collaboration with cross-functional teams to define system requirements, buildproduct roadmaps, and ship high-impact releases.
- European Software Solutions FirmFull-Stack Developer (AI + Web Systems)January 2019 - January 2021 (2 years)- Developed and maintained web applications using React, Node.js, and PostgreSQL for SaaS and internal business tools.- Implemented automation workflows using early n8n/Make integrations to reduce data entry and manual reporting tasks.- Collaborated with senior engineers to architect backend APIs and streamlinedatabase performance.- Improved front-end UI/UX and optimized application performance for faster load times and smoother user flows.- Supported several client deployments and contributed to documentation, testing, and code quality improvements
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Education
- Bachelor of EngineeringTechnical University of Berlin2018Bachelor of Engineering
- Warsaw University of Technology2018